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  <div class="section" id="numpy-ma-maskedarray-flags">
<h1>numpy.ma.MaskedArray.flags<a class="headerlink" href="#numpy-ma-maskedarray-flags" title="Permalink to this headline">¶</a></h1>
<p>attribute</p>
<dl class="attribute">
<dt id="numpy.ma.MaskedArray.flags">
<code class="sig-prename descclassname">MaskedArray.</code><code class="sig-name descname">flags</code><a class="headerlink" href="#numpy.ma.MaskedArray.flags" title="Permalink to this definition">¶</a></dt>
<dd><p>Information about the memory layout of the array.</p>
<p class="rubric">Notes</p>
<p>The <a class="reference internal" href="#numpy.ma.MaskedArray.flags" title="numpy.ma.MaskedArray.flags"><code class="xref py py-obj docutils literal notranslate"><span class="pre">flags</span></code></a> object can be accessed dictionary-like (as in <code class="docutils literal notranslate"><span class="pre">a.flags['WRITEABLE']</span></code>),
or by using lowercased attribute names (as in <code class="docutils literal notranslate"><span class="pre">a.flags.writeable</span></code>). Short flag
names are only supported in dictionary access.</p>
<p>Only the WRITEBACKIFCOPY, UPDATEIFCOPY, WRITEABLE, and ALIGNED flags can be
changed by the user, via direct assignment to the attribute or dictionary
entry, or by calling <em class="xref py py-obj">ndarray.setflags</em>.</p>
<p>The array flags cannot be set arbitrarily:</p>
<ul class="simple">
<li><p>UPDATEIFCOPY can only be set <code class="docutils literal notranslate"><span class="pre">False</span></code>.</p></li>
<li><p>WRITEBACKIFCOPY can only be set <code class="docutils literal notranslate"><span class="pre">False</span></code>.</p></li>
<li><p>ALIGNED can only be set <code class="docutils literal notranslate"><span class="pre">True</span></code> if the data is truly aligned.</p></li>
<li><p>WRITEABLE can only be set <code class="docutils literal notranslate"><span class="pre">True</span></code> if the array owns its own memory
or the ultimate owner of the memory exposes a writeable buffer
interface or is a string.</p></li>
</ul>
<p>Arrays can be both C-style and Fortran-style contiguous simultaneously.
This is clear for 1-dimensional arrays, but can also be true for higher
dimensional arrays.</p>
<p>Even for contiguous arrays a stride for a given dimension
<code class="docutils literal notranslate"><span class="pre">arr.strides[dim]</span></code> may be <em>arbitrary</em> if <code class="docutils literal notranslate"><span class="pre">arr.shape[dim]</span> <span class="pre">==</span> <span class="pre">1</span></code>
or the array has no elements.
It does <em>not</em> generally hold that <code class="docutils literal notranslate"><span class="pre">self.strides[-1]</span> <span class="pre">==</span> <span class="pre">self.itemsize</span></code>
for C-style contiguous arrays or <code class="docutils literal notranslate"><span class="pre">self.strides[0]</span> <span class="pre">==</span> <span class="pre">self.itemsize</span></code> for
Fortran-style contiguous arrays is true.</p>
<dl class="field-list simple">
<dt class="field-odd">Attributes</dt>
<dd class="field-odd"><dl class="simple">
<dt><strong>C_CONTIGUOUS (C)</strong></dt><dd><p>The data is in a single, C-style contiguous segment.</p>
</dd>
<dt><strong>F_CONTIGUOUS (F)</strong></dt><dd><p>The data is in a single, Fortran-style contiguous segment.</p>
</dd>
<dt><strong>OWNDATA (O)</strong></dt><dd><p>The array owns the memory it uses or borrows it from another object.</p>
</dd>
<dt><strong>WRITEABLE (W)</strong></dt><dd><p>The data area can be written to.  Setting this to False locks
the data, making it read-only.  A view (slice, etc.) inherits WRITEABLE
from its base array at creation time, but a view of a writeable
array may be subsequently locked while the base array remains writeable.
(The opposite is not true, in that a view of a locked array may not
be made writeable.  However, currently, locking a base object does not
lock any views that already reference it, so under that circumstance it
is possible to alter the contents of a locked array via a previously
created writeable view onto it.)  Attempting to change a non-writeable
array raises a RuntimeError exception.</p>
</dd>
<dt><strong>ALIGNED (A)</strong></dt><dd><p>The data and all elements are aligned appropriately for the hardware.</p>
</dd>
<dt><strong>WRITEBACKIFCOPY (X)</strong></dt><dd><p>This array is a copy of some other array. The C-API function
PyArray_ResolveWritebackIfCopy must be called before deallocating
to the base array will be updated with the contents of this array.</p>
</dd>
<dt><strong>UPDATEIFCOPY (U)</strong></dt><dd><p>(Deprecated, use WRITEBACKIFCOPY) This array is a copy of some other array.
When this array is
deallocated, the base array will be updated with the contents of
this array.</p>
</dd>
<dt><strong>FNC</strong></dt><dd><p>F_CONTIGUOUS and not C_CONTIGUOUS.</p>
</dd>
<dt><strong>FORC</strong></dt><dd><p>F_CONTIGUOUS or C_CONTIGUOUS (one-segment test).</p>
</dd>
<dt><strong>BEHAVED (B)</strong></dt><dd><p>ALIGNED and WRITEABLE.</p>
</dd>
<dt><strong>CARRAY (CA)</strong></dt><dd><p>BEHAVED and C_CONTIGUOUS.</p>
</dd>
<dt><strong>FARRAY (FA)</strong></dt><dd><p>BEHAVED and F_CONTIGUOUS and not C_CONTIGUOUS.</p>
</dd>
</dl>
</dd>
</dl>
</dd></dl>

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